Written by our friends over at Sound Devices, acclaimed manufacturer of digital recorders and field mixers.
Since it began shipping, Sound Devices has received numerous inquiries concerning audio interconnection with the RED One camera and our field mixers and recorders. We elected to bring an example of the Red camera in-house for audio testing.
We are fortunate to have friends at Fletcher Chicago. Fletcher has an extensive arsenal of cameras and they were kind enough to arrange for a Red for our testing needs. We picked up unit #529 with build 15, v2.2.5 on May 21, 2008. This unit appeared fresh out-of-the box.
Disclaimer: While we believe our measurements to be accurate and empirical, note that we do not guarantee that the performance we observed is the actual performance of every camera. You may want to do your own tests to verify performance for your specific application.
Microphone Preamplifiers
Based on information received directly from Red and from the many user reports on the Red forum, Sound Devices elected to concentrate audio tests on performance of the camera’s line-level inputs. Our brief listening test of the microphone inputs verified that they are not suitable for anything but a scratch track, especially when phantom is activated. Whether microphone preamplifier performance is a hardware issue or something that will change in the future with a firmware revision is unclear. It is no doubt that Tom Fletcher appreciates that we didn’t take apart the brand new camera body to see for ourselves.
Sound Devices recommends connecting to the Red One at line-level only.
Interconnection and Cables
The Red has four, locking TA3-F connectors, each of which can be switched between line-level or mic-level. In the mic-level position, gain is menu-adjustable between 20 dB and 54 dB. In the line-level position input sensitivity is fixed with no adjustment.
The Red Camera is supplied with short XLR-to-TA3 adapter cables. These cables have resistors built-in to change impedance and reduce signal level. When used without these cables, the Red inputs can be characterized as "-10″ level (full scale on the meter = +8.2 dBu) with 600 ohm input impedance.
With the supplied cables, the inputs can be characterized as accepting signals just below full line-level (full scale on the meter = +19.4 dBu) with 2000 ohm input impedance.
